AN INTERNAL FIXATOR FOR SPINE

摘要

Disclosed herein is a bone fixation apparatus, comprising a bone screw having a head; a cap for supporting the top of the head of the bone screw; a compression bush for pushing the cap; a receiver member having a bore in which the cap and the compression bush are accommodated and the head of the screw is hitched, and a U-shaped channel through which a support bar is accommodated; a bar fixing nut threadedly coupled to the receiver member to fix the support bar, wherein the cap has a shape of a belleville spring in which a diameter of a lower end thereof is smaller than that of an upper end, and an upper surface thereof is concavely inclined toward an inner radial direction and a lower side thereof is formed with a curvature contacting an outer circumferential surface of the head.